This invention relates to protective coatings for fruits.
Fruits which are ordinarily sticky because of the presence of surface deposits of sugar or for other reasons are subject to certain deleterious changes. Such fruits include dates, figs, candied fruits, and dried fruits such as prunes, apricots and raisins. Fruits of this type tend to clump or stick together, creating difficulties in their handling in packaging and in use. Additionally, when they are stored for long periods of time, the fruits may become moldy and inedible. To solve these problems, a presently employed commercial means is to coat the fruit with dustings of sugar, corn syrup solids or dextrose. This detracts from the natural appearance of the fruit and adds undesirable carbohydrates. It has also been previously proposed that the fruits be coated with various coatings such as pectins, waxes and fats. However, these coatings have not been able to prevent the fruits from sticking together when they are applied in the limited amounts necessary to avoid altering the appearance and flavor of the fruit. Coatings such as glycerol or polysaccharides, for use in place of or in addition to the above, have also been suggested and have not solved the problem.
Previous coatings such as waxes, glycerol and the like have been applied to "dry" fruits, that is, fruits which are free of surface moisture. For example when raisins are graded, cleaned and processed commercially, one of the last steps is a wash in clear, warm water. Thus, there is surface moisture on the fruit at the time of packaging, which aids somewhat in helping the fruit to flow into the filling machines. But the previously disclosed fatty/waxy/polysaccharide and gel materials are not compatible with water. Therefore, in order to obtain a surface coating using such materials, processed raisins must stand for a period of several hours, normally about 24 hours, to allow surface moisture to be absorbed into the raisins before they may be coated, thus adding to the time, labor, expense and equipment required in processing.
There thus remains a need for a coating that gives increased free-flowability to sticky fruits while not detracting from the appearance and taste and while eliminating a time-consuming processing step.